In a conventional image forming method which has been widely employed in copying machines, printers, facsimile, and the like, an electrostatic latent image formed on an electrostatic latent image supporting member, such as a photosensitive member, is developed by a toner, and the resulting toner image is transferred onto a recording member, such as recording paper, for image formation. In recent years, a full-color image forming apparatus for reproducing a multicolor image by superposing plural colors one over another has been put in practical application.
In such a full-color image forming apparatus, an electrostatic image is formed in dot units on an organic photosensitive member which is negatively charged by digital writing, for example, light beam irradiation, and the latent image is developed in reverse by using negatively chargeable magenta, cyan, and yellow toners, and black toner as required. Toner images of different colors thus obtained are superposed one over another so as to be reproduced as a multicolor image.
Such full-color image formation is largely utilized in reproducing pictures, photographs, graphic images and, as mentioned above, color toners of plural colors are superposed one over another for multicolor image reproduction. Such multicolor imaging is widely employed not only for image formation on recording paper, but also for image formation on overhead projector transparent sheets (OHP sheet). However, even though the color toner has distinct color reproducibility when a color toner image is formed on the recording paper, there is a problem that if such an image, formed on an OHP sheet, is actually projected onto a screen, the image becomes somewhat blackish, thus showing reduced color reproducibility.